Atlantic slavery and British ports
The Atlantic Slave Trade and Britain
The seventeenth and eighteenth centuries saw Britain become the dominant power in the transatlantic slave trade. The Royal African Company was chartered in 1672, establishing Britain’s systematic involvement in the trade in enslaved people. Between 1672 and 1713, the Company transported an estimated 100,000 enslaved Africans across the Middle Passage to the Americas. When its monopoly was broken in 1698, independent merchants from Bristol and Liverpool rapidly expanded the trade. By the mid-eighteenth century, British ships were carrying more enslaved Africans than those of any other nation.
The major British slave-trading ports were London, Bristol and Liverpool. These cities grew wealthy on the profits of the triangular trade — manufactured goods to West Africa, enslaved Africans to the Americas, colonial produce (sugar, tobacco, cotton) back to Britain. This wealth funded the building of churches, country houses, banks and public institutions. Historians including David Olusoga have documented how deeply embedded slave-trade profits were in British urban development and institutional life.
Olaudah Equiano was born around 1745, enslaved and transported to the Americas as a child, and eventually purchased his own freedom. His autobiography, The Interesting Narrative of the Life of Olaudah Equiano (1789), was one of the earliest accounts written by a formerly enslaved person to reach a wide British audience. It sold thousands of copies and was used by abolitionists to demonstrate the humanity and suffering of enslaved Africans. Equiano toured Britain giving lectures and became a leading figure in the campaign against the slave trade.
Black Communities in Eighteenth-Century Britain
The slave trade brought an estimated 10,000–15,000 Black people to Britain by the mid-eighteenth century — largely enslaved servants brought back by planters, merchants and naval officers returning from the colonies. London had the largest Black community, concentrated in areas like St Giles and the East End. Not all were enslaved: some were free, some were formerly enslaved people who had gained freedom, and some were mixed-race children of British colonists.
Ignatius Sancho was born on a slave ship around 1729 and eventually settled in England, where he became a celebrated writer, letter-writer and abolitionist. He was the first Black person known to have voted in a British parliamentary election. His published letters attracted attention from literary figures including Laurence Sterne. Like Equiano, Sancho used his literacy and connections to challenge the dehumanising premises of slavery from within British society.
In 1772, Lord Mansfield delivered a landmark ruling in the Somerset case. James Somerset, an enslaved man brought from the colonies to England, had escaped and been recaptured. His case was taken up by the abolitionist Granville Sharp. Mansfield ruled that Somerset could not be forcibly removed from England. The ruling was widely — but incorrectly — interpreted as making slavery illegal in England. In practice, it only prevented forcible removal; enslaved people could still be held in England, and slavery in the colonies was entirely unaffected.
Nevertheless, the Somerset case had symbolic importance. It galvanised the growing abolitionist movement and gave enslaved people in England a legal foothold. The Sons of Africa, an abolitionist group formed in the 1780s by Equiano and Ottobah Cugoano, drew on the case in their campaigning. The movement connected Black activists with white abolitionists including Thomas Clarkson and William Wilberforce in building the campaign that eventually produced the Slave Trade Act of 1807.
The Zong Massacre and the Path to Abolition
In 1781, the crew of the slave ship Zong threw 132 enslaved Africans overboard alive to claim insurance money, since the company’s policy paid for cargo “lost at sea” but not for those who died of disease. The case came to court in 1783 as an insurance dispute — the legal question was the value of the “cargo,” not the murder of 132 human beings. Granville Sharp tried but failed to bring a murder prosecution. The Zong massacre became one of the most powerful pieces of evidence used by abolitionists to expose the moral horror of the slave trade to British audiences.
The formal abolition of the slave trade in 1807 did not end slavery in the British colonies — that came with the Slavery Abolition Act of 1833. However, the 1807 Act ended Britain’s legal involvement in the trade and was followed by the Royal Navy actively suppressing slave trading by other nations. The compensation paid on abolition in 1833 went to slaveholders, not to the people who had been enslaved — an aspect of the settlement that historians have continued to examine.
The Sons of Africa was founded in the 1780s by Equiano, Ottobah Cugoano and other Black activists. It represents one of the earliest examples of Black political organisation in Britain. The group wrote petitions to Parliament, gave lectures, and worked alongside white abolitionists in what became a broad coalition movement. Their role is sometimes understated in traditional accounts that focus primarily on white parliamentary campaigners.
The growth of Black communities in eighteenth-century Britain fits uneasily within conventional migration narratives because the movement was coerced, not voluntary. Enslaved people did not choose to come to Britain. Yet once in Britain, individuals like Equiano and Sancho demonstrated agency, built networks, and contributed to intellectual and political life in ways that shaped British history. This tension between coerced arrival and active contribution is central to understanding this period of migration history.
The loss of the American colonies after 1783 also contributed to Black community growth in Britain: some Black Loyalists who had fought for the Crown were evacuated to Britain and Canada. This added another layer to a diverse Black British population that came from multiple routes and circumstances, not a single story.